The final version of Android 7.1.2 has rolled out to Pixel phones and some Nexus devices, but the Nexus 6P is finally getting the final beta build. The update is rolling out right now to members of the Android Beta testing program.
The update is only 25.4MB, which makes sense since you’re not even going up a version number. There are no new features in this build. It simply brings the Nexus 6P up to the final version of 7.1.2. Being on the final version will put you back on track for regular OTA updates.